package com.ship.util;

import com.ship.core.ConstantsPwdKey;
import org.apache.commons.codec.binary.Base64;

import javax.crypto.Cipher;
import java.io.ByteArrayOutputStream;
import java.security.*;
import java.security.interfaces.RSAPrivateKey;
import java.security.interfaces.RSAPublicKey;
import java.security.spec.PKCS8EncodedKeySpec;
import java.security.spec.X509EncodedKeySpec;
import java.util.HashMap;
import java.util.Map;

/**
 * RSA 加密解密
 */
public class RSAUtils {
    /** *//**
     * 加密算法RSA
     */
    public static final String KEY_ALGORITHM = "RSA";

    /** *//**
     * 签名算法
     */
    public static final String SIGNATURE_ALGORITHM = "MD5withRSA";

    /** *//**
     * 获取公钥的key
     */
    private static final String PUBLIC_KEY = "RSAPublicKey";

    /** *//**
     * 获取私钥的key
     */
    private static final String PRIVATE_KEY = "RSAPrivateKey";

    /** *//**
     * RSA最大加密明文大小
     */
    private static final int MAX_ENCRYPT_BLOCK = 117;

    /** *//**
     * RSA最大解密密文大小
     */
    private static final int MAX_DECRYPT_BLOCK = 128;

    /** *//**
     * <p>
     * 生成密钥对(公钥和私钥)
     * </p>
     *
     * @return
     * @throws Exception
     */
    public static Map<String, Object> genKeyPair() throws Exception {
        KeyPairGenerator keyPairGen = KeyPairGenerator.getInstance(KEY_ALGORITHM);
        keyPairGen.initialize(1024);
        KeyPair keyPair = keyPairGen.generateKeyPair();
        RSAPublicKey publicKey = (RSAPublicKey) keyPair.getPublic();
        RSAPrivateKey privateKey = (RSAPrivateKey) keyPair.getPrivate();
        Map<String, Object> keyMap = new HashMap<String, Object>(2);
        keyMap.put(PUBLIC_KEY, publicKey);
        keyMap.put(PRIVATE_KEY, privateKey);
        return keyMap;
    }

    /** *//**
     * <p>
     * 用私钥对信息生成数字签名
     * </p>
     *
     * @param data 已加密数据
     * @param privateKey 私钥(BASE64编码)
     *
     * @return
     * @throws Exception
     */
    public static String sign(byte[] data, String privateKey) throws Exception {
        byte[] keyBytes = Base64.decodeBase64(privateKey);
        PKCS8EncodedKeySpec pkcs8KeySpec = new PKCS8EncodedKeySpec(keyBytes);
        KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);
        PrivateKey privateK = keyFactory.generatePrivate(pkcs8KeySpec);
        Signature signature = Signature.getInstance(SIGNATURE_ALGORITHM);
        signature.initSign(privateK);
        signature.update(data);
        return Base64.encodeBase64String(signature.sign());
    }

    /** *//**
     * <p>
     * 校验数字签名
     * </p>
     *
     * @param data 已加密数据
     * @param publicKey 公钥(BASE64编码)
     * @param sign 数字签名
     *
     * @return
     * @throws Exception
     *
     */
    public static boolean verify(byte[] data, String publicKey, String sign)
            throws Exception {
        byte[] keyBytes = Base64.decodeBase64(publicKey);
        X509EncodedKeySpec keySpec = new X509EncodedKeySpec(keyBytes);
        KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);
        PublicKey publicK = keyFactory.generatePublic(keySpec);
        Signature signature = Signature.getInstance(SIGNATURE_ALGORITHM);
        signature.initVerify(publicK);
        signature.update(data);
        return signature.verify(Base64.decodeBase64(sign));
    }

    /** *//**
     * <P>
     * 私钥解密
     * </p>
     *
     * @param encryptedData 已加密数据
     * @param privateKey 私钥(BASE64编码)
     * @return
     * @throws Exception
     */
    public static byte[] decryptByPrivateKey(byte[] encryptedData, String privateKey)
            throws Exception {
        byte[] keyBytes = Base64.decodeBase64(privateKey);
        PKCS8EncodedKeySpec pkcs8KeySpec = new PKCS8EncodedKeySpec(keyBytes);
        KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);
        Key privateK = keyFactory.generatePrivate(pkcs8KeySpec);
//        Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm());
        Cipher cipher = Cipher.getInstance("RSA/ECB/PKCS1Padding");

        cipher.init(Cipher.DECRYPT_MODE, privateK);
        int inputLen = encryptedData.length;
        ByteArrayOutputStream out = new ByteArrayOutputStream();
        int offSet = 0;
        byte[] cache;
        int i = 0;
        // 对数据分段解密
        while (inputLen - offSet > 0) {
            if (inputLen - offSet > MAX_DECRYPT_BLOCK) {
                cache = cipher.doFinal(encryptedData, offSet, MAX_DECRYPT_BLOCK);
            } else {
                cache = cipher.doFinal(encryptedData, offSet, inputLen - offSet);
            }
            out.write(cache, 0, cache.length);
            i++;
            offSet = i * MAX_DECRYPT_BLOCK;
        }
        byte[] decryptedData = out.toByteArray();
        out.close();
        return decryptedData;
    }

    /** *//**
     * <p>
     * 公钥解密
     * </p>
     *
     * @param encryptedData 已加密数据
     * @param publicKey 公钥(BASE64编码)
     * @return
     * @throws Exception
     */
    public static byte[] decryptByPublicKey(byte[] encryptedData, String publicKey)
            throws Exception {
        byte[] keyBytes = Base64.decodeBase64(publicKey);
        X509EncodedKeySpec x509KeySpec = new X509EncodedKeySpec(keyBytes);
        KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);
        Key publicK = keyFactory.generatePublic(x509KeySpec);
//        Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm());
        Cipher cipher = Cipher.getInstance("RSA/ECB/PKCS1Padding");
        cipher.init(Cipher.DECRYPT_MODE, publicK);
        int inputLen = encryptedData.length;
        ByteArrayOutputStream out = new ByteArrayOutputStream();
        int offSet = 0;
        byte[] cache;
        int i = 0;
        // 对数据分段解密
        while (inputLen - offSet > 0) {
            if (inputLen - offSet > MAX_DECRYPT_BLOCK) {
                cache = cipher.doFinal(encryptedData, offSet, MAX_DECRYPT_BLOCK);
            } else {
                cache = cipher.doFinal(encryptedData, offSet, inputLen - offSet);
            }
            out.write(cache, 0, cache.length);
            i++;
            offSet = i * MAX_DECRYPT_BLOCK;
        }
        byte[] decryptedData = out.toByteArray();
        out.close();
        return decryptedData;
    }

    /** *//**
     * <p>
     * 公钥加密
     * </p>
     *
     * @param data 源数据
     * @param publicKey 公钥(BASE64编码)
     * @return
     * @throws Exception
     */
    public static byte[] encryptByPublicKey(byte[] data, String publicKey)
            throws Exception {
        byte[] keyBytes = Base64.decodeBase64(publicKey);
        X509EncodedKeySpec x509KeySpec = new X509EncodedKeySpec(keyBytes);
        KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);
        Key publicK = keyFactory.generatePublic(x509KeySpec);
        // 对数据加密
//        Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm());
        Cipher cipher = Cipher.getInstance("RSA/ECB/PKCS1Padding");
        cipher.init(Cipher.ENCRYPT_MODE, publicK);
        int inputLen = data.length;
        ByteArrayOutputStream out = new ByteArrayOutputStream();
        int offSet = 0;
        byte[] cache;
        int i = 0;
        // 对数据分段加密
        while (inputLen - offSet > 0) {
            if (inputLen - offSet > MAX_ENCRYPT_BLOCK) {
                cache = cipher.doFinal(data, offSet, MAX_ENCRYPT_BLOCK);
            } else {
                cache = cipher.doFinal(data, offSet, inputLen - offSet);
            }
            out.write(cache, 0, cache.length);
            i++;
            offSet = i * MAX_ENCRYPT_BLOCK;
        }
        byte[] encryptedData = out.toByteArray();
        out.close();
        return encryptedData;
    }

    /** *//**
     * <p>
     * 私钥加密
     * </p>
     *
     * @param data 源数据
     * @param privateKey 私钥(BASE64编码)
     * @return
     * @throws Exception
     */
    public static byte[] encryptByPrivateKey(byte[] data, String privateKey)
            throws Exception {
        byte[] keyBytes = Base64.decodeBase64(privateKey);
        PKCS8EncodedKeySpec pkcs8KeySpec = new PKCS8EncodedKeySpec(keyBytes);
        KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);
        Key privateK = keyFactory.generatePrivate(pkcs8KeySpec);
//        Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm());
        Cipher cipher = Cipher.getInstance("RSA/ECB/PKCS1Padding");
        cipher.init(Cipher.ENCRYPT_MODE, privateK);
        int inputLen = data.length;
        ByteArrayOutputStream out = new ByteArrayOutputStream();
        int offSet = 0;
        byte[] cache;
        int i = 0;
        // 对数据分段加密
        while (inputLen - offSet > 0) {
            if (inputLen - offSet > MAX_ENCRYPT_BLOCK) {
                cache = cipher.doFinal(data, offSet, MAX_ENCRYPT_BLOCK);
            } else {
                cache = cipher.doFinal(data, offSet, inputLen - offSet);
            }
            out.write(cache, 0, cache.length);
            i++;
            offSet = i * MAX_ENCRYPT_BLOCK;
        }
        byte[] encryptedData = out.toByteArray();
        out.close();
        return encryptedData;
    }

    /** *//**
     * <p>
     * 获取私钥
     * </p>
     *
     * @param keyMap 密钥对
     * @return
     * @throws Exception
     */
    public static String getPrivateKey(Map<String, Object> keyMap)
            throws Exception {
        Key key = (Key) keyMap.get(PRIVATE_KEY);
        return Base64.encodeBase64String(key.getEncoded());
    }

    /** *//**
     * <p>
     * 获取公钥
     * </p>
     *
     * @param keyMap 密钥对
     * @return
     * @throws Exception
     */
    public static String getPublicKey(Map<String, Object> keyMap)
            throws Exception {
        Key key = (Key) keyMap.get(PUBLIC_KEY);
        return Base64.encodeBase64String(key.getEncoded());
    }


/*    private static final String DEFAULT_PUBLIC_KEY = "MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQDosvH1gCpQTTZLXGMcSeeqDjWuDVY0+Aab1VbtGJqWdkPd32D4hEUwFjVJ+FJbq7UpvFFDQ3k2y2n/1rzxWapFk/e+BNNCSKP9e6+Of1SLs83So27dgiAeAKmdQoxwfXrgvP1/QRMJJ0i6m3CRRyTlXO+cMGbYqRv1iTT9uaRolQIDAQAB";
    private static final String DEFAULT_PRIVATE_KEY = "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";

    public static void main(String[] args) throws Exception {
        test();
        // testSign();
//		encodeRequest(null);
    }

    static void test() throws Exception {
//        System.err.println("公钥加密——私钥解密");
//        String source = "这是一行没有任何意义的文字，你看完了等于没看士大夫反反复复反反复复反反复复反反复复多发时段发生的发生的发生的发生的发生的发生的发生的发生的发生的发生的发生的发生的发生的发生的发生，不是吗？这是一行没有任何意义的文字，asdfsdafsdafsfasdfdfsa你看完了等于没看，不是吗？这是一行没有任何意义的文字，你看完了等于没看，不是吗？这是一行没有任何意义的文字，你看完了等于没看，不是吗？这是一行没有任何意义的文字，你看完了等于没看，不是吗？这是一行没有任何意义的文字，你看完了等于没看，不是吗？这是一行没有任何意义的文字，你看完了等于没看，不是吗？";
//        System.out.println("\r加密前文字：\r\n" + source);
//        byte[] data = source.getBytes();
//        byte[] encodedData = RSAUtils.encryptByPublicKey(data, DEFAULT_PUBLIC_KEY);
        byte[] xxx = Base64.decodeBase64("rOkHAW194SPLruStOScmgPUEoDJFP6Bte5wAaAYoEiihU2fll1Fl5hbVWS91g1PNJgNz5Ld++n09XXc2roXZZSVrcg+IO5Ry50HaXlhiaMWtZ/APVvL11ItDeNygSqD6JB7+z6o8YTkG/gswL/elsOHfiRQa9zDR8tZIZs+TsAM+3NsCUvAjbVFIiRhxuWQ/m5kw6zSJOWh8OHSYHHH9b2TIotOv5sNEJPtVc6KikmJT4TpiFi6T8A6Y7DRX5NAcrhjziG87q6kHPB+9SgbtSq1AAiepHOoV3ku/iOvcGTi6uhc0HTmUDZdifkwXBqDFuwK05Ybt3z/LSym2DlKj5w==");
        //System.out.println("加密后文字：\r\n" + new String(xxx));
        byte[] decodedData = RSAUtils.decryptByPrivateKey(xxx, ConstantsPwdKey.PRIVATE_KEY);
        String target = new String(decodedData);
        System.out.println("解密后文字: \r\n" + target);
    }*/
}
